Infrared cameras are widely available from a number of sources and are routinely used to provide security or perform other functions at night and in other low-light situations. Conventional infrared cameras typically generate images in which the background is darker in color, and people, animals, or heated objects appear much brighter in the images than the darker background. “Infrared camouflage” attempts to mask the presence of people, animals, or heated objects in infrared images so that they appear darker in color and are harder to distinguish from the background in the infrared images. Among other things, infrared camouflage could be used to help protect military or law enforcement personnel from being easily detected in dangerous environments.
Some conventional attempts to provide infrared camouflage are based on covering a person in a thermal suit formed from material that reduces his or her thermal signature. However, requiring a person to wear a thermal suit often reduces the person's flexibility of movement. Also, since there is little thermal discharge from the thermal suit, the person's body temperature can rise to uncomfortable or dangerous levels. In addition, the reflectivity of the thermal suit often increases when the thermal suit gets wet, which can lead to easier detection.
Other conventional attempts to provide infrared camouflage for vehicles or other objects involve the use of heating or cooling plates that are mounted directly on the objects. The temperatures of the plates can be changed adaptively to camouflage the objects against the background. However, these approaches require the use of heavy plates and are therefore bulky and costly. These approaches can also be difficult to implement successfully and are often dedicated to specific vehicles or systems.